021
AXNT20 KNHC 131706
TWDAT

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
1805 UTC Thu Jun 13 2024

Tropical Weather Discussion for North America, Central America
Gulf of Mexico, Caribbean Sea, northern sections of South
America, and Atlantic Ocean to the African coast from the
Equator to 31N. The following information is based on satellite
imagery, weather observations, radar and meteorological analysis.

Based on 1200 UTC surface analysis and satellite imagery through
1653 UTC.

...SPECIAL FEATURES...

Heavy Rainfall over the southeastern Gulf of Mexico, portions of
the Florida Peninsula, and the western Atlantic:

Abundant tropical moisture is surging northward from the western
Caribbean, across the southeastern Gulf of Mexico, also over
portions of Florida, and across the adjacent western Atlantic
waters. This moisture resides to the southeast of a surface
trough that extends from near 30.5N78W southwestward to east-
central Florida north of Cape Canaveral to an elongated area of
low pressure (Invest AL90) near 30N79.2W with a pressure of 1010
mb. A surface trough continues from this elongated area of low
pressure southwestward to near Tampa, Florida to 24N88W and to
the central Bay of Campeche. Also, upper-level diffluent flow is
present across the region. As a result, numerous showers and
scattered thunderstorms are present southeast of the trough over
the western Atlantic from 27.5N to 31N between 73W and 80W and
south of 25N west of 77W including the Straits of Florida, the
majority of the Florida Key, over central Cuba and its adjacent
waters. In addition numerous thunderstorms are quickly
developing over the Yucatan Peninsula and the Bay of Campeche
south of 22N. Cloud to surface lightning, strong gusty winds,
rough seas and low visibility are ongoing within this convective
activity over these areas. The shower and thunderstorm activity
is expected to continue across the region through at least Fri.
Mariners transiting these regions should exercise caution.
Please refer to bulletins and forecasts from your local weather
forecast offices for specific local information.

Heavy Rainfall over Central America and Mexico:
A barotropic Central American Gyre (CAG) is rapidly developing.
Observations are indicating that heavy rainfall is already
occurring before the main event that is forecast to begin Sunday
morning, June 16 through the morning of Friday June 21. The
persistence of moist onshore flow in the Pacific basins of
Guatemala, Chiapas, Honduras and in El Salvador will favor 3-4
days of intermittent rounds of heavy precipitation.

...TROPICAL WAVES...

A central Atlantic tropical wave has its axis along 32W from
03N to 12N. It is moving westward near 15 kt. No significant
convection is depicted with this tropical wave.

An Atlantic tropical wave has its axis along 48W from 02N
to 14N, moving westward at about 15 kt. Scattered convection is
depicted from 00 to 06N between 44W and 49W.

A Atlantic tropical wave has its axis along 61W south of
12N eastern Venezuela. It is moving west at 10 to 15 kt.
Scattered showers are near the wave axis south of 12N.

A western Caribbean tropical wave has its axis along 81W south of
14N, moving westward at 5 to 10 kt. Related numerous moderate to
scattered strong convection is depicted south of 12N and east of
81W and over the eastern Pacific near the coast of Panama.

...MONSOON TROUGH/ITCZ...

The monsoon trough axis extends from near 13.5N17W to 08N26W.
The ITCZ begins at 08N26W and continues to near 08N31W, and from
08.5N34W to 07N47W, and from 08N51W to 08.5N58W. Numerous
moderate to strong convection emerging off West Africa and
extends from 03N to 10N between the coast and about 22W. This
convection is most likely in advance of the next tropical wave.

...GULF OF MEXICO...

Please read the Special Features section for information about
the ongoing heavy rainfall over the southeastern Gulf of Mexico
and the upcoming rainfall event over Mexico.

A stationary front extends from northeast Florida to just south
of Louisiana, and westward from there to inland Texas near
Houston/Galveston area. A trough extends from near Tampa Bay,
Florida to the central Bay of Campeche. Scattered to numerous
showers and thunderstorms are southeast of the trough impacting
most of the southeastern Gulf and waters just offshore the
northern Yucatan Peninsula. Outside of convection, light to
gentle generally variable winds west of the trough, with
moderate south to southwest winds east of the trough. Seas are 1
to 3 ft west of the trough, and 3 to 4 ft east of the trough,
except to 5 ft near the Yucatan Channel due to a southeast
swell. Hazy conditions are over the SW Gulf due to ongoing
agricultural fires are in Mexico.

For the forecast, the aforementioned surface trough is expected
to gradually weaken through late Fri. Looking ahead, a broad
area of low pressure is forecast to form over the southwestern
Gulf of Mexico this weekend or early next week. Environmental
conditions appear conducive for gradual development of this
system, and a tropical depression could form during the early or
middle part of next week while it moves slowly westward or west-
northwestward. Increasing winds and building seas are expected
with this system.

...CARIBBEAN SEA...

Please read the Special Features section above for more
information about the upcoming Rainfall event over Central
America and Mexico.

Numerous moderate to isolated strong convection is depicted at
this time north of 17.5N between 18W and 82W due to a surge of
tropical moisture. Outside of convection, the pressure gradient
between Atlantic high pressure, lower pressures in the deep
tropics, and the trough of low pressure across the southeastern
Gulf of Mexico is resulting in moderate to fresh east to
southeast winds over most of the basin, with the exception of
the central basin, where winds are fresh to strong, including
between Cuba and Jamaica. Seas range from 7 to 9 ft over the
central Caribbean and 4 to 6 ft elsewhere, except 3 to 5 ft east
over the southwestern Caribbean.

For the forecast, high pressure located NE of the area combined
with the Colombian low and the passage of tropical waves will
support fresh to strong trade winds across the central Caribbean
through tonight. Moderate to fresh southeast winds are expected
over the northwestern Caribbean likely through Fri as a trough
of low pressure remains over the eastern Gulf of Mexico.
Otherwise, scattered showers and thunderstorms are forecast to
continue across portions of the northwestern Caribbean through
the rest of the week as a surge of tropical moisture persists
across the region. Looking ahead, expect increasing winds and
building seas over the western Caribbean, including the Gulf of
Honduras, over the upcoming weekend as a broad area of low
pressure is forecast to form over the southwestern Gulf of
Mexico.

...ATLANTIC OCEAN...

Please read the Special Features section above for more
information about the heavy rainfall over the western Atlantic
and near and over portions of the Florida peninsula.

A stationary front extends from low pressure of 1017 mb that is
well north of the area near 37N61W southwestward to just north
of the Florida Georgia line. Deep convection over the western
Atlantic is described above in the Special Features section.
Fresh to locally strong winds and 5 to 7 ft seas are north of
28.5N to 31N between 73W and 77.5W. A surface trough supported
by an upper-level is analyzed from near 30N46W to 26N45W and to
20N48W. Broken to overcast mostly mid-level clouds with embedded
with scattered showers and thunderstorms are depicted from 21N
to 29N between 42W and 47.5W. A weak trough extends from 22N54W
to 16.5N60W. Scattered moderate convection is depicted from 21N
to 22.5N between 50W and the trough axis. Another weak surface
trough is analyzed from 29N60.5W to 21N59W. Scattered moderated
convection is depicted from 21N to 25N between the trough axis
and 56W

Other than the features above, strong high pressure of 1033 mb
located well north of the discussion area in the vicinity of the
Azores has an associated ridge that reaches southwestward to the
central Bahamas, disrupted by the troughs. Mainly gentle to
moderate winds and seas of 3 to 6 ft seas dominate the basin
west of 35W. Moderate to fresh trade winds east of 35W, except
for fresh to strong northeast winds from the Cabo Verde Islands
to the Canary Islands, including along the coast of Africa. Seas
are 5 to 7 ft across this area. Saharan Air dominates the lower
to middle atmosphere across the Atlantic from about 10N to 20N
and roughly between Africa and the Lesser Antilles.

For the forecast west of 55W, an elongated area of low pressure
offshore the coast of Florida is producing a large area of
disorganized showers and thunderstorms. Despite strong upper-
level winds, some gradual development is possible while the
system moves northeastward offshore of the southeastern U.S.
coast during the next couple of days. The showers and
thunderstorms will be numerous in coverage and contain gusty
winds and frequent lightning at times over most of the western
part of the forecast waters, mainly W of a line from 31N70W to
the central Bahamas. Expect for little change with this
convective activity through at least Fri. Fresh to strong
southerly winds are expected over the western Atlantic ahead of
this system during the next couple of days. As the low pressure
departs, high pressure will build southward over the western
Atlantic beginning this weekend and into early next week.

$$
KRV